Microsoft has appealed to the US Supreme Court to overturn a ruling that the firm is an illegal monopoly.
It sent the petition to the court two days before the case was to be sent to a new judge to decide what penalty the firm should face.
Microsoft has also asked the appeals court that currently has the case to hold off any action until the Supreme Court decides whether to take the case, says company spokesman Mr Vivek Varma.
A federal appeals court in June threw out a US District Court judge's order breaking the company in two.
It said a new lower court judge should hold hearings to fashion a punishment, which could still include a break-up. The firm has been accused of harming consumers and stifling competition.
In its Supreme Court appeal, Microsoft again takes up the question of whether District Judge Thomas Penfield Jackson was biased against the company.
It says his entire ruling should be thrown out because the appeals court found that he violated the judicial ethics code.
"On that basis, Microsoft argues that the district judge should have been disqualified from any further role in the case as of the time the earliest violation occurred," Microsoft told the court.
The appeals court strongly condemned Judge Jackson's actions, but said that nevertheless Microsoft still acted as "an illegal monopoly."